Jump-spark ignition system.



E. S. LINCOLN. J UMP SPARK IGNITION SYSTEM. APPLIOATION FILED DBO.5,1907..

917,736, I Patented Apr.6, 1909.

Inventor: wc'ineaeay @M d,- QLQW; fi/iawmcd I 51 J 6% UNITED STATEEl T OFFICE.

EDWIN LINCOLN, OF BROOKLINE, MASSACHUSETTS.

JUMP-SPARK IGNITION SYSTEM.

Specification of Letters Patent.

Patented April 6, 1909.

Application filed December 5, 1907. Serial No. 405,218.

' as the jump spark system. The principal'use of such jump spark i nition systems today is in connection with t e ignition systems ofexplosive engines, and the like, but such ignition system is adapted for use in many other connections.

As is well known, Where the jump spark ignition systems are employed in explosive engines, a gaseous mixture in, the cylinder of an explosive engine is ignited at the desired moment by means of an electric spark,

formed by the passage of a high tension current across the gap separating the terminals .of a spark plug coated in said cylinder. The hightension current employed for this purpose is ordinarily that generated in the secondary winding of an induction coil by the rapid making and breaking of the circuit of the primary winding by means of a vibrator, or similar device. The current for energizing the Cprimary winding of the induction COll an for operating the vibrator is commonly that derivedfrom dry or storage batteries and the like. v

So far as .I am aware lo,w tension d namos have not hitherto been successfu ly employed for thepurpose of supplying current or energizing an induction 0011 used in connection with a jump spark ignition system. The reason for this, as understood by the writer is explained as follows.- In the operation of an induction coil the interruption of the current by which the primary winding is energized, by the operation of the vibrator, results in the generation in that winding 'of a self-induced current which ordinarily has an electro motive force considerably higher than that of the batter by which the energizing current was su p ied. While 1 am not able to state definite y the technical reasons which are res onsible for such unsatisfactory results, it is elieved that the self-induced currents, which are generated in the rimary Winding of the inductioncoil when t e enering to produce a sluggish action of the inducthey may be discharged through a battery or an analogous source of electricity. The

result is a largely increased sluggishness of action of the current in the primary coils of a generator operated induction coil, as compared with the action of .the same when energized by a battery, or the like, which im pairs the strength of the current induced in the secondary windings of the coil, and rendering the coil as a whole unreliable as a means for energizing the ignition system. Thus the use of the dynamo as an energizing means for the induction coil has been found unsatisfactory.

My invention aims to render possible the satisfactory employment of a low tension dynamo for energizing the primary winding of an induction coil used in connection with a jump spark ignition system.

To this end my invention consists in the use in connection with the ignition system of electrical ap aratus designed to overcome the difiiculties ereinabove described as tendtion coil energized by a dynamo.

In the drawing I have resented a figure illustrating diagrammatica ly, the invention, in its'preferred form.

In said figure 1 is a direct current shunt Wound generator of any approved type. From one brush 2' the circuit leads to one terminal 3 of the primary winding of an induction coil. From the other terminal 4 of said primary winding the circuit leads through the vibrator 5 and the inductive resistance 6 back to the other brush 7 of gen-' erator 1. At 8 and 9 are shown the adja ,cently located spark points connected to the terminals of the secondary winding of the induction coil. In the circuit between the primary winding and the generator is the in-' ductiv'e resistance 6, so constructed as to combine low --resi stance with high inductllO induced currents from ance. The conductors between the generator brushes and the terminals "of the primary Winding of the induction coil are con- 'nected by the non-inductive resistance 10,

which embodies high resistance with little or no inductance. This non-inductive resistance 10 is located so that the inductive resistance coil 6 is situated between one of the generator terminals and the point at which non-inductive resistance 10 engages the conductor leadingfrom that terminal to one terminal of the induction coil. To use technical language it may be stated that the inductive resistance isin series with the generator, and both are in series with the primary winding of the induction coil; the non-inductive resistance and the induction coil being both connected in parallel as to the generator and the inductive'resistance.

The manner of operation of my invention is asfollows. Assuming generator 1 to be rotating, .current will be generated which will proceed from one brush 7 through the inductive resistance 6, the Vibrator 5, and the primary winding of the induction coil, back to the other brush 2. Owing to the comparatively steady and continuous character of the current produced by the generator the inductive resistance will not retard the free flow of current through the same. A small amount of current will fiow between the main leads by means of the non-inductive resistance 10, but enough resistance should be provided by the same to render such flow, at the normal operating voltage of negligible and harmless amount. As the primary winding of the induction coil is energized the vibrator 5 will be caused to act, causing the separation of the contact points of the same and consequently interrupting the flow of current. The result of this interruption of current will be to produce in the primary winding a self induced current which is of a relatively high voltage, and which, except for my invention would tend to discharge itself through, and thus come into inters ference with the currents generated in the generator, or-be impeded by the windings thereof. Owing, however, to the fluctuating character of this self induced current it is choked oil from the generator by the inductive resistance 6, leaving as a more available path of discharge the connection 10, which, although of low conductive capacity for currents of the normal operating voltage of the generator, will be of ample conductive capacity to permit the discharge therethrough of currents having the relatively high voltagc of the self. induced currents produced in the primary windings. As a result of the increased facility of the discharge of the self the primary winding of the induction coil, the efiiciency of the induction coil as a whole is increased.

In many cases an improvement in the operation of a generator energized induction electric activities of the induction coil. Such condenser is shown in the figure, being connected in at 12 and 13 so as to shunt the vibrator points. Its use is indicated merely for the purpose of illustrating my system in its most eflicient form, but the use of a condenser of itself is well known and forms no part of my invention.

Where my Invention is employed in connectionwithignitionworkforexplosivemulticylinderedfengines it is evident that a timer must be used for the purpose of controlling the sparking at the proper cylinder, and the time of suchsparking. Such timer may operate in the usual manner, and is not shown in the drawings, as being no part of my vention.

Having described my invention, what I claim is:

1. In an ignition system, in combination, a

generator; an induction coil having a rimary winding, an inductive resistance, an a noninductive resistance; said non inductive resistance being in parallel with the primary winding of the induction coil, and both noninductive resistance and the primary winding of the induction coil being in series with the inductive resistance and the generator.

2. In a jump spark ignition system, in combination with a direct current generator,

and an induction coil adapted to be energized thereby, a non-inductive resistanceelectrically interconnecting the conductors connecting the generator andthe induction coil, and an inductive resistance located in one of said conductors between the generator and the point at which said non-inductive resistance is connected to said conductorv 3. In a jump spark ignitionsystem, in combination, with a direct current generator and an induction coil adapted to be energized thereby, an inductive resistance in circuit with the generator and the primary winding of the induction coil, and a non-inductive resistance adapted to electrically connect the terminals of the primary winding of said induction coil.

4. In an induction coil, means electrically connecting the terminals 'of the primary winding, said connection embodying a resistance sufficient to tial leakage of the in nation coil energizing current therethrough but insufiicient to proreclude the substanvent the discharge therethrough of the self-v induced currents induced in the primary windings.

5. In an ignition system, in combination with a generator, and an induction coil having the terminals of its primary winding electrically connected in operative relation with said generator, a non-inductive resistance permanently connecting the terminals of said primary winding, said non-inductive resistance having a conductive capacity. adapted to prevent the substantial passage therethrough of current at the normal operating voltageof the generator, but permitting the free discharge through the same of 15 y In testimony whereof I afiix my signature 20 in presence of two witnesses.

EDWIN S. LINCOLN.

\Vitnesses:

NATHAN B. DAY, v -WILLIAM A. COPELAND. 

